Nested Structure: When members of a structure are defined as structure type, these are called nested structures. For example: struct info { char s_name[15]; char f_name[15] ; char city[15] ; int age; }; struct p_data { info s1; info s2; float x; }; p_data rec; In the above example, info structure is defined with four members. The structure p_data is defined after the info and...